Transducer manipulators for crack indication and the like on-line on hot blanks operate in a hostile environment and are therefore provided with extensive means for heat radiation protection, normally water-cooling. This results in a high weight for the movable structure used to support the transducer, with consequent problems in the response time of the transducer to tracking instructions.
A plurality of manipulator solutions are known, most of them based on one or more rotating, oscillating of self-oscillating transducers.